Gonorrhea is a wily foe. But doctors may soon have another drug to fight the sexually transmitted infection that’s become resistant to nearly every antibiotic thrown its way. In clinical trials, a new antibiotic was effective at stopping the bacteria that causes the disease.

A single oral dose of the drug, called zoliflodacin, cured 96 percent of people who had gonorrhea infections in the urinary and genital organs, researchers report in the Nov. 8 New England Journal of Medicine. In comparison, 100 percent of patients given ceftriaxone — the remaining antibiotic that’s effective against the disease in the United States — were successfully treated.

Caused by Neisseria gonorrhoeae, gonorrhea can be passed from an infected person to a sexual partner or from an infected mother to her baby at birth. The consequences of the infection are especially severe for women, who can develop pelvic inflammatory disease and become infertile (SN: 6/10/00, p. 376), and for babies, who can lose their sight. The United States had more than half a million new gonorrhea cases reported in 2017, up about 75 percent from the historical low point in 2009. Worldwide, an estimated 78 million new gonorrhea infections occur each year.

In the United States, doctors treat an infection with a combination of ceftriaxone and another antibiotic called azithromycin. But bacterial strains resistant to ceftriaxone have cropped up in other countries, raising concerns of untreatable gonorrhea.

Zoliflodacin blocks proteins that N. gonorrhoeae needs to replicate its genetic material. In a Phase II clinical trial to determine the drug’s effectiveness, 141 participants were split into three groups. One set got ceftriaxone. Of the two groups given either a two-gram or three-gram dose of zoliflodacin, 55 of 57 and 54 of 56 people, respectively, were cured of infections.